Type-writer platen-release mechanism.



C. GABRIELSON.

TYPE WRITER PLATEN RELEASE MECHANISM.

APPLICATION FILED JULY 15. 1915.

1 ,217,4=36.- Patented Feb. 27, 7.

EETS-SHEE C. GABRIELSON. TYPE WRITER PLATEN RELEASE MECHANISM.

APPLICAHON FILED JULY |5 |9l5- 1,217,436. Patented Feb. 27, 1917.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE.

CARL GABRIELSON, OF SYRACUSE, NEW YORK, ASSIGNOR TO L. C. SMITH & BROS. TYPEWRITER COMPANY, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Feb. 27, 1917.

Application filed July 15, 1915. Serial No. 40,055.

To all whom it may concern:

Be it known that I, CARL GABRIELsoN, a citizen of the United States, and resident of Syracuse, county of Onondaga, State of New York, have invented certain new and useful Improvements in Type-Writer Platen- Release Mechanism, of which the follow-- 'ing is a specification.

The object of the present invention is to provide a device by means of which the platen may be released from the control of its ratchet wheel and turned through any angle desired, independently of the ratchet wheel, and reconnected with the ratchet wheel at any point in its rotation. In one adjustment of my improved release mechanism the platen, platen shaft and platen ratchet are connected to turn together in either direction while in another adjust ment the platen is normally connected with the ratchet wheel but may be disconnected and moved independently by simply turning the platen shaft in the desired direction. This improved release mechanism has certain advantages over prior constructions which will be hereinafter more particularly pointed out.

Referring to the drawings,

Figure 1 is a plan view showing one end of a typewriter plate-n and part of the carriage on which it is mounted;

Fig. 2 is a longitudinal sectional view on the line 22, Fig. 1;

Fig. 3 is a side view of the platen ratchet and clutch showing the platen connected rigidly to the ratchet wheel; I

Fig. 4 is a similar View showing the platen released from the ratchet wheel; and

Fig. 5 is a detail.

Referring to the drawings, 10 indicates a typewriter platen having the usual resilient covering surrounding the platen core 11. The platen is mounted as usual on a shaft 12 which turns in suitable bearings in the carriage frame 13. On the outer end of the shaft is the usual knob 14 for turning the platen by hand.

Permanently connected with the end of the platen is a platen head comprising a disk 15, an outer annular plate 16, having a hub 17 and an intermediate ring member 18 The parts 15, 16 and 18 are secured together, as by screws 19 and form a casing for the clutch and a bearing for the ratchet wheel, as will be presently described.

The ratchet wheel 20 is a ring provided W1th the'usual ratchet teeth and mounted in an annular recess in the parts 16 and 18. The ratchet wheel is normally yieldingly held against rotation by the holding pawl 21 and is operated, when desired, by the usual line space pawl 22. i

Within the ratchet wheel a series of balls or rollers 23 is located, the balls or rollers being partly in a recess in the ring 18. A wedge 21 is normally pressed in between the balls or rollers by a spring 25 which is seated in a cup 26 mounted in the head. The Wedge and cup are arranged in radial lines with respect to the axis of the platen. The inner end of the wedge is in the form of a yoke 27 having its lower ends connected by a cross piece 28. An opening 29 through which the platen shaft passes is thus provided.

The cross piece or bridge 28 is preferably beveled on inner surface and the platen shaft has a correspondingly inclined flat face 30, as shown in Fig. 2. The platen shaft is longitudinally movable with respect to the platen to assume either of two positions and it is yieldingly held in either position by a spring detent 31 which cooperates with. grooves 32, 33. The spring detent is suitably connected with the carriage and as shown is an arm on the sliding plate 34 which locks one end of the platen in its hearing.

The plate 15 on the platen head has a hub 35 projecting into the platen and provided with a diametrical recess 36 within which is located a pin 37 rigidly connected with the platen shaft 12 (Figs. 2 and 5). The recess 36 is wide at its inner end and narrow at its outer end, the narrow end being of just sufiicient width to receive the pin 37 while the wider end permits the pin to turn in either direction from its central position sufliciently to release the platen from its clutch, as will be 'presentlydescribed. Within the hub 35 a collar 38 is preferably fixed on the platen shaft. This collar limits the outward movement of platen shaft and permits it to be moved inward until the detent 31 engages the groove 32.

The operation of the platen clutch is as follows: ,'When it is desired to lock the ratchet wheel to the platen, as in ordinary writing in which the lines are evenly spaced, the platen shaft is pulled outward by means of the knob until it assumes the position shown in Fig. 2, in which the spring detent 31 lies in the groove 33. The detent will prevent the shaft from moving inward while the collar 38 will prevent it from moving farther outward. 7

When it is desired to release the platen from its ratchet wheel for the purpose of variably spacing the lines, the platen shaft is pushed inward until the spring detent 31 snaps into the groove 32. In this position of the platen shaft the incline 30 on the shaft comes into contact with, or closely approaches, the cross bar 28, but it does not withdraw the wedge 24 from the roller clutch unless the platen shaft is turned. Upon turning the platen shaft in either direction, the wedge is withdrawn from the rollers, as shown in Fig. 4, and the rollers are thus freed from their .grip upon the ratchet wheel, permitting the platen to be turned independently of the ratchet wheel; The inward movement of' the platen shaft carries the pin 37 into the wide part of the diametrical slot 36, which permits the shaft to be turned sufficiently to release the clutch. The pin then engages the hub and turns the platen positively to the desired extent. On releasing the knob of the platen shaft it will be rotated to normal position by the spring 25 acting through the bar 28 and incline face 30 and the wedge will relock the platen to the ratchet wheel.

It will be seen that when the platen shaft is pushed in and held by engagement of the detent 31 with the groove 32 the platen will be normally locked to the ratchet wheel by means of the wedge 24 and spring 25 but will be unlocked and free to be turned in either direction upon turning the lmob 14 in the direction of movement desired. In this adjustment of the parts the platen is normally in condition for the usual or standard line spacing and still may be turned any fractional space in either direction by simply turning the knob. There is provided, therefore, means for attaining either normal line spacin or universal spacing without adjusting rom one to the other, the ratchet wheel always effecting normal spacing while by simply turning the knob irregular spacing may be effected in either direction. When it is desired to eliminate the irregular spacing and to turn the platen through regular spaces by means of the knob, the platen shaft is pulled out to the position shown in Fig. 2.

Having described my invention what I claim and desire to secure-by Letters-Patent is,

1. In a typewriter, the combination with a platen shaft, a platen, a ratchet wheel mounted on the end of the platen, a holding pawl cooperating with the ratchet wheel, and a clutch for connecting the ratchet wheel with the platen, said shaft being movable axially to two positions, of a detent for holding said shaft in either position, means whereby the rotation of said shaft, when in one position will release the clutch and rotate the platen independently of the ratchet wheel, and means whereby the platen is locked to the ratchet wheel by means of the clutch when the shaft is in the other position. I

2. In a typewriter, the combination with a platen shaft, a platen, a ratchet wheel mounted on the end of the platen, a holding pawl cooperating with the ratchet wheel, and a clutch for connectin the ratchet wheel with the platen, said 0 utch comprising a series of rollers within the ratchet wheel, and a radially arranged wedge for expanding the rollers against the ratchet wheel, of means for withdrawing the wedge upon therotation of the shaft in either direction, whereby the platen is freed from the ratchet wheel, and means for connecting the shaft with the platen to rotate the latter when released from the ratchet wheel.

3. In a typewriting machine, the combination with a platen, of a platenhead secured thereto, and a shaft I extending through the platen head into the platen,

said shaft being movable longitudinally, means whereby the shaft is connected to the platen to turn the same when in one position' and movable relatively to the platen when in another position, and means whereby said shaft is held yielding in either of said two positions.

4. In a typewriting machine, the combination with a platen, of a platen head socured thereto, and a shaft extending through the platen head into the platen, said shaft being movable longitudinally, and means whereby the shaft is connected to the platen to turn the same when in one position and movable relatively to the platen when in another position, said means comprising a pin extending radially from the platen shaft and opera-ting in a wedgeshaped opening in a part connected with the platen, said pin being incapable of movement relatively to the platen when in the smaller end of the opening and movable slightly in either direction relatively to the platen when in the larger end of the opening.

5. In a typewriting machine, the combinationwith a platen, of a platen head secured thereto, and a shaft extending through the platen head into the platen, said shaft being movable longitudinally, means whereby the shaft is connected to the platen to turn the same when in one position and movable relatively to the platen when in another position, said means comprising a pin extending radially from the platen shaft and operating in a wedgeshaped opening in a part connected with the platen, said pin being incapable of movement relatively to the platen when m the smaller end of the opening and movtween rollers to render the clutch operative,

a cross bar connected to said wedge, and a platen shaft extending through the platen head and having an inclined surface adapted to cooperate with said cross bar, said platen shaft being movable to two positions with respect to the platen and platen head and said incline and cross bar being so arranged that the rotation of the shaftwhen in one position will release theclutch while the rotation of the shaft when the other position will not aifect the clutch.

7. In a typewriter, the combination with a platen, of a platen shaft movable axially with respect to the platen, a detent for holding said shaft in .either of two axial positions with respect to the platen, means for connecting the platen shaft to turn the platen coincidently with the turning of the shaft in one position thereof, and means whereby the shaft may turn slightly in either direction independently of the platen in the other position of said shaft.

8. In a typewriter, the combination with a platen, with respect to holding said shaft in either 'of two axial positions with respect to the platen, means for connecting the platen shaft to turn the platen coincident ly with the turning of the shaft in one position thereof, and means combination with of a platen shaft movable axially the platen, a detent for either direction independently of the platen in the .other position of said shaft, said shaft being provided with means for releasing. the platen from its ratchet wheel when in the latter position.

9, In a typewriting machine, the combination with a platen, 'a platen shaft movable axially with respect to the platen, a

platen ratchet wheel, and means for moving said ratchet wheel for line spacing, said ratchet wheel being normally operated to turn the platen for line spacing in all positions of said shaft, of means whereby the platen may be released from the ratchet wheel in one position of the shaft and turned for independent spacing.

10. In a typewriting machine, the combination with a platen, a platen shaft movable axially with respect to the platen, means for holding said shaft yieldingly in either of two positions, a platen ratchet wheel and means for moving said ratchet wheel for line spacing, said ratchet wheel being normally operated to turn the platen for line spacing in each of said positions of said shaft, of means whereby the platen may be released from the ratchet wheel when the shaft is in one of said positions and turned for independent spacing.

11. In a typewriting machine, the combination with a platen, a platen shaft movable axially with respect to the platen, means for holding said shaft yieldingly in either of two positions, a platen ratchet wheel and means for moving said ratchet wheel for line spacing, said ratchet wheel being normally operated to turn the platen for line spacing in each of said positions of said shaft, of means whereby the platen may be released from the ratchet wheel by the rotation of said shaft and turned for independent spacing.

In testimony whereof I aflix my signature.

CARL GABRIELSON.

whereby the shaft may. turn slightly in 

